1. Technology Field
The present invention generally relates to network tapping devices. In particular, the present invention relates to a network tap/aggregator and associated devices, hardware and software, that are configured for Power Over Ethernet (“POE”) based operation.
2. The Related Technology
The dependence upon the use of data networks to transmit and receive data at high data rates has led to a corresponding interest in the ability to perform real-time monitoring and analysis of that data, or network traffic, so that performance of the network can be evaluated, and problems identified and resolved. Such data monitoring and analysis necessitates the ability to access the network data stream without disrupting data transmission and the operation of the network.
To this end, hardware devices known as “network taps” are employed and configured such that network data can be captured for analysis without interrupting operation of the network. In general, network taps receive a stream of network data and make a copy of the data while allowing the original stream to pass through to its destination. The copied data is forwarded to a network analyzer or other monitoring device for evaluation. This is typically a real time process that continually occurs while the network tap is operating.
While network taps have generally proven useful in enabling the monitoring and analysis of network traffic, significant problems remain with typical network taps. One problem of particular concern is that network taps typically require an external power source for operation. Because the network tap relies on an external power source, an interruption of power to the network tap generally results in a corresponding interruption in data flow through the network. Even a very short term interruption in power to the network tap will force a typical data network as a whole to re-initialize, often using complex auto-negotiation and discovery algorithms. This initialization process can take from a few seconds to several minutes, depending on the network topology. As a result, an interruption of power to the network tap can severely impair operation of the entire data network.
Thus, the external power supply to the network tap is a significant failure point in the system. Unfortunately, disconnection of such external power supplies is a relatively common occurrence. In many cases, disconnection of the external power supply to the network tap occurs because the network tap and power supply are located in a place where personnel may inadvertently, or mistakenly, unplug the power supply. These challenges are only magnified where multiple network taps are implemented in the communication network or other system. As noted above, this lack of fault tolerance in many high speed data communication networks is a major concern that remains largely unaddressed.
Other problems concern aggregation devices that are often employed in conjunction with network TAPs. For example, typical aggregation devices incorporate a single port configuration. Thus, a user that desires to aggregate multiple data streams is compelled to use a relatively large number of aggregators, and a significant amount of cabling, in order to obtain the desired aggregation results.